1. Field of the Invention
The present invention relates to a fuel cell stack.
2. Discussion of the Background
A solid-polymer electrolyte fuel cell, for example, includes power generation units. Each of the power generation units includes a membrane electrode assembly (MEA) and a pair of separators sandwiching the MEA therebetween. The MEA includes an electrolyte membrane, which is a polymer ion-exchange membrane, and an anode electrode and a cathode electrode sandwiching the electrolyte membrane therebetween. This type of fuel cell is used in a fuel cell stack, which usually includes a stack of a certain number (for example, hundreds) of such power generation units.
The fuel cell stack, which includes a stack of the power generation units, also includes a terminal plate, an insulation plate, and an end plate that are stacked at each end of the stack of the power generation units in the stacking direction.
For example, Japanese Unexamined Patent Application Publication No. 2002-184449 describes a solid polymer electrolyte fuel cell stack. The solid polymer electrolyte fuel cell stack includes a stack of power generation units that are stacked in a horizontal direction. Each of the power generation units includes a pair of electrodes sandwiching a solid polymer electrolyte membrane therebetween and a pair of separators sandwiching the pair of electrodes therebetween. A heat insulating layer is interposed between a power generation unit that is disposed at least one end of the stack in the stacking direction and a terminal plate disposed outside the power generation unit.
The solid polymer electrolyte fuel cell stack has the heat insulating layer between the terminal plate and the power generation unit at the end in the stacking direction